pgsql: Fix translatable string construction

Fix translatable string construction

In a few places, we were constructing translatable strings consisting of
elements list by adding one element at a time and separately a comma.
This is not great from a translation point of view, so rewrite to append
the comma together with the corresponding element in one go.

Author: Peter Smith <smithpb2250(at)gmail(dot)com>
Author: Álvaro Herrera <alvherre(at)kurilemu(dot)de>
Discussion: https://postgr.es/m/CAHut+Pvp7jYcaiZ3pXedXgLcWZWDBLXFUK05JtZpGv3Mj=UOjw@mail.gmail.com

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/3692a622d3fdf8a44af0c0b541a51163ead314f1

Modified Files
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src/backend/catalog/pg_subscription.c | 22 ++++++++++++++--------
src/backend/commands/tablecmds.c | 15 ++++-----------
src/backend/replication/logical/relation.c | 13 ++++++-------
3 files changed, 24 insertions(+), 26 deletions(-)